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stent ffice.

Letters P atent No. 77.437, elated May 5, 1858.

IMPROVEMENT IN THIMBLE-PUIILER.

@Ligt dgemlt referat it it time ttttts tant nu making ont m5 its sante.

TO ALL WIIOM IT MAY CONCERN:

Be it known that I, ALBERT F. ALLEN, ofthe city and county ofProvidence, and State of Rhode Island, have invented a new and improvedThimble Puller for removing the thimbles" or ferr'uleswfrom the tubes ofsteam-boilers; and I dov hereby declare that the following is 'a full,clear, and exact description of the same, reference beinghad to theaccompanying drawings, making part of .this specification, in which-Figurel is a longitudinal view of my machine', as used for removing theordinary thimble or ferrule from boiler-tubes.

Figure 2 is a like view of the same, as usedfor removing screw-thimbles,which are screwed instead ofbeing driven into the end of boiler-tubes. Il

Figures 3, 4, 5, 6, 7, 8, are details of the constructionv of 'mymachine.

Similar' letters indicate corresponding parts in all the said figures.

The thimbl'e, (or ferrule, as it is sometimes called,) above referredt0is a ring of wrought iron (gnerally,) which is driven or screwed intothe end of the boiler-tube, to keep it expanded in the due-sheet andpreserve the joint which is formed therewith around the end of the tube.In consequence of the moisture andgases which are generated within theboiler, the said thimbles become in a short time corroded to that extentthat they become as immovably fixed in their place as though they were apart of the tube itself,- so much so in fact that it has hitherto beenfound necessary to cut the thimble in two pieces in order to remove it,which, without i exception, is attended with such injury to thc endofthe tube as to require resetting, and in most cases piercing out toprovide for-the removal of the'injured portion at the end. By means ofthe machine which I have devised, and which is herein described, I amenabled to readily removel the thimble from the end of the tube, nomatter to what'extent itis corroded, without injury to the joint formedwith the due-sheet around it, much less to the end of the tube. v A

My invention, -for this purpose, consists of a set of expansible catchesor jaws, en a suitable mandrel or stock, that are capable oi' attachingthemselves firmly to the thinible in the tube; a surroundingsleeve whichserves as a fulcrum by resting against the contiguous portion 'of thetube or duo-sheet; and a screw-thread on the mandrel, with a scrcwfnutturning thereon, and bearing against the sleeve or fulcrum in such amanner, that, by the turning of' the nut, the thimble attached to thecatches or jaws is forcibly drawn,by the force thus exerted upon thescrew, from within the end of the tube. i

And my invention further consists in constructing the said catches orjaws with external serrated or scored surfaces, so as to bc capable ofattaching themselves by forcible expansion to the inner surface of athimble, such as is described, andin combination therewith, suitablemeans for attaching a wrench or other turning-lever to the mandrelholding suohjaws, for the purpose lof unscrewing and removing suchthimbles as are secured in the end of the tube by screwing. v

In' the said drawings, A, iigs. 1 and 2, is the thimble, which is astout non-collapsable ring of wrought metal, slightlyr tapering on theoutside, which is either turned smooth or has a screw-thread cut uponit, according to the mode ol` its use. l

E E E are the enpansible catches or jaws, extending longitudinally fromthe hub or collar T ofthe mandrel II, eachjaw being, for the sake ofstrength, formed as shownin figs. 7 and 8, with stout trunnions or varmsb 6, forming part of the same, upon which the jaw turns in the collar T.These trunnion's are fitted into the two parts of the collar, as shownclearly in'gs. 2, 3, and 4,the movable part T of said collar, beingsecured vin its place by means of the pin S, (fig. f2.)l The mandrel H,(ofwhich the collar T forms a para) hasa hole, I, longitudinally throughthe centre, (figs. 3 and 4,) for the reception ofthe stem d of theadjusting or expandingwedge I", which forms a sort of' triangular headthereto, and which fits nicely between the several catches, and by meansof the thumb-screw nut 7c, iig. 2, at the end of the said stem, ismaderto press the said wedges outward, and eiicct their expansion so asto fasten to the thimble in the tube. Alsleeve, M is tted to slideeasily on the said mandrel, `and encloses the collar and a portion ofthe catches or jaws, the oce of which is to afford a rest or supportaround the thimble, againstwhich force may be exerted to withdraw thethimble from the tube.

The tubular portion of the mandrel is furnished with a. screw-thread, onwhich a large hexagonal nut, P, turns, and has a bearing against therear end ofthe said sleeve, by menus of which, byturning the screen, thejaws or ca-tclies E, and the thimble to which they are attached, aredrawn into the sleeve and out of the boiler-tube.

In case the thimble is screwed into lthe end of the boiler-tube so tha-tlit cannot be drawn out by the applica.- tion of' direct longitudinalpressure, es in the manner just described, .the guidejmvs are inade toattach themselves to the interior surface of the thimble, by theexipansin elluded to, by making the exterior face o1` bearing a ofsndjnivs with teeth, or otherwiseroughened, to prevent slipping, and toindent and 'catch upon the s'nid surface of the thimble, and the saidmandrel H is squared t'G, to receive n; Wrench by which it, with itsjews, may be turned to unscrew the thiinble from the tube. The coller ofthe mandrel may also be formed to recevca-wrenelb or may be drilled toreceive a. lever or rod by which toturn the mandrel for the unscrewingof the tliimble.

In the use of the apparatus for removing serewthin1bles,'the sleeve isunnecessary.

What I claim as my invention, is l The combination of the expnnsiblecatches orjaws E E E, or their equivalent, the expanding-wedge F, thesleeve M, und the screwlmendrel H, and nut P, constructed substantiallyas described for the purpose set forth;

` ALBERT F. ALLEN.'

Witnesses:

ISAAC A. BROWNELL', WILLIAM BROWNELL.'

